This invention relates to an improved birdfeeder of the general type disclosed in my prior U.S. Pat. No. 4,331,104 granted May 25, 1982.
The birdfeeder of the aforesaid prior patent is particularly effective as a squirrel proof birdfeeder because of its overall geometry. The birdfeeder of the prior patent comprises a clear plastic body, a metal cover and a metal hanger. The body has an outer shell having upper and lower spherical wall portions and an inner arch having curved upper dome and lower wall portions, a pair of feeding trays, each having floor and sidewall portions and a bottom access opening or fly up entry. The upper wall portion has at least one filling port. The cover is bell-shaped with a central hole therethrough and is provided with a rubber grommet in seated engagement with the central hole. The hanger has a straight rod portion with external threads at one end and a hook portion at the other end. The grommet is in engagement with the straight rod portion of the hanger, and the cover is movable lengthwise of the rod portion between a lower position in which the cover covers the filling port and an upper position in which the filling port is exposed to permit seeds to be poured into the feeder. The rod passes through central aligned holes in the inner arch and the upper spherical wall portion. A nut is in threaded engagement with the threads on the hanger, and the hook portion of the hanger is a substantial distance above the hole in the upper spherical wall portion.
Squirrels will attempt to gain access to seed in the feeder by raising the cover to expose the filling port and/or by entering the feeder through the fly up entry.
The attempt by the squirrels to rise the cover is resisted by the grommet between the cover and the rod portion of the hanger, but eventually, due to grommet wear, this resistance tends to lessen until the squirrels may be successful in raising the cover and thereby getting at the seed in the feeder through the filling port.
In one of its features, it is an important object of the present invention to thwart squirrels' efforts to raise the cover to expose the filling port by providing a cover lock to resist raising of the cover to expose the filling port.
In attempting to gain access to seed in the feeder through the bottom access opening or fly up entry, a squirrel clings to the hanger by its hind legs, stretches its body around the cover and the body portion of the birdfeeder to the fullest possible extent and then releases its grip on the hanger and simultaneously tries to flip itself upwardly through the access opening, to grab a feeding tray. This is a precarious process involving an almost impossible feat of contortion and aerobatics.
It is another important object of the present invention to decrease the chances that a squirrel might gain access to the interior of the feeder through the fly up entry by providing a helper spring which causes the feeder to move suddenly upwardly when the squirrel releases its grip on the hanger, so that at the critical instant when the squirrel is flipping itself upwardly, the fly up entry is not where the squirrel thinks it is.